Equation REF  is minimized via 200 updates of \(O\)  using Adam [1]} with parameters \(\eta =2e^{-3}\) , \(\beta _1=0.9\) , and \(\beta _2=0.999\) . As in STROTSS, we parameterize \(O\)  as a laplacian pyramid with 8 levels. Doing so allows the average color of large regions to be controlled by a small number of parameters (coefficients in coarse levels of the pyramid).
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